D: Learn it. Fun to play while discussing ideas, or when wasted (surprisingly).
I really like Zombicide. A zombie survival game, but not something you'd do quickly, about 4-5 hours per game isn't out of the normal. Goal is to survive, and you have to find weapons, achieve missions, and kill zombies all at the same time, either in team, or solo.
Also, Axis & Allies. Again, a long game, one match takes about 2 days. It's like Risk, but heavier, bigger, and set in WWII.
Dominion. Goal is to get as many points as possible, and to buy points you have to buy cards that allow you to buy more cards, or get more money. It's difficult at first, but easy when you know it.